Draw graphics in a 3D graph

Mmm if that works yes, but I don´t know, what I need is to draw some points into a graph with 3 axis (x,y,z), I suppose that for that I need some 3D graphics. Write now I´m using this code:

using System;
using System.Windows.Media;
using System.Windows.Media.Media3D;
using System.Windows;
using System.Windows.Media.Animation;
using System.Windows.Controls;
using System.Windows.Input;

namespace DataVisualization
{

public static void Main()
        {
            Application app = new Application();
            Window w = new Window();
            Viewport3D vp = new Viewport3D();

            // Create our scene.
            //

            ModelVisual3D scene = new ModelVisual3D();
            AxisAngleRotation3D rotation = new AxisAngleRotation3D(
                new Vector3D(0, 0, 1) /* z-direction */, 0 /* degrees */);
            plotVisual.Transform = new RotateTransform3D(rotation);

            scene.Children.Add(plotVisual);

            //
            // Add lights.
            //
            .....


            // Add scatter plot
            //

            ModelVisual3D plotVisual = MakePlot(c_numPoints, 10 /* size */);

            AxisAngleRotation3D rotation = new AxisAngleRotation3D(
                new Vector3D(0, 0, 1) /* z-direction */, 0 /* degrees */);
            plotVisual.Transform = new RotateTransform3D(rotation);

            scene.Children.Add(plotVisual);

            vp.Children.Add(scene);

            w.Content = vp;
            w.Show();

            app.Run();
        }

It´s not the whole code, but it´s part of it, with this code I can show in my window "w" the point´s i want but I show them in an Application Window, but I can´t see the axis, If I close the Application and try to call it again the program will show the next Error: System.Windows.Application can´t be opened more than once, and.. I don´t know why, there´s an option to shut down the application but, when I use this It still doesn´t work.

So... if you know a different way to do it I´ll appreciate your opinion, thanks.